Humans and Pollution (1.5)
What is pollution?
Pollution is released by human activities that cause destruction of the environment. Pollution can be:
Pollution comes in two forms: Primary and Secondary.
|
Pollution Categories
Point vs Non-point SourcePoint source pollutant = a pollutant that is released at a specific, single clearly identifiable site. Usually easily managed.
What is a non-point source pollution |
POPs vs BiodegradeablePOPs (Persistent organic pollutants) = pollutants (usually manufactured chemicals) that are resistant to being broken down and remain active in ecosystem for a long time. They bioaccumulate over time.
Biodegradable wastes causes harm? |
Acute vs Chronic PollutantsAcute pollutants = large amounts of the pollutant are released quickly, causing harm. Usually stops or only occurs periodically. Examples include:
|
Direct vs Indirect Measurement
Pollution can be measured directly or indirectly.
Direct measurement = require measuring the pollutant specifically. Examples include:
Direct measurement = require measuring the pollutant specifically. Examples include:
- Acidity of rainwater
- amount of a gas (carbon monoxide or sulphur oxide) in the atmosphere
- Amount of lead in the soil
- Amount of nitrates and phosphates in the water or soil
- Heavy metal concentrations in water or soil
- how a fish population changes based on oxygen concentration of the water
- presence or absence of an indicator species over time (biotic index)
Pollution Management Strategies
Pollution management takes three basic levels/ or ways:
- by altering human activity
- by regulating or preventing the release of the pollutant
- by working to clean up or restore damaged ecosystems.
You should be able to have specific examples at EACH level of management for the following issues:
|
DDT Case Study
First raised as an issue to the general public by Rachel Carson's Silent Spring, DDT is a persistent organochloride insecticide. It will kill any insect it comes in contact with it. It was initially developed as a way to control the mosquito population and thereby control malaria. It was extremely effective at doing this. Unfortunately it was also demonstrated to bioaccumulated and therefore biomagnify within an ecosystem. It is thought DDT kills about 2.7 million people a year, mostly children under 5. However, malaria infects 300-500 million a year, killing about 0.2% a year (600,000-1,000,000). DDT was banned in the USA in 1972 on the advice of the Environmental Protection Agency, and has since been banned for public health reasons in most MEDCs. However, it is still used as a mosquito control in many LEDCs, specifically in tropical areas.
DDT, Eggshells, and me
The question remains- should it be banned? What is the evidence for environmental issues compared to the cost of mosquito borne diseases? Here are some possible points to get you started, but don't take my points as gold, there are many others.
DDT, Eggshells, and me
The question remains- should it be banned? What is the evidence for environmental issues compared to the cost of mosquito borne diseases? Here are some possible points to get you started, but don't take my points as gold, there are many others.
Pro Banning
25 Years After DDT Ban- Environmental Defense Fund |
Against Banning
Bring Back DDT!- Science Magazine Editorial Use of DDT for Malaria control - United Nations |